/*
 * @Descripttion: 
 * @version: 
 * @Author: weihua.yao
 * @Date: 2020-02-25 14:57:02
 * @LastEditTime: 2020-02-25 15:04:23
 */
console.log(typeof undefined) //undefined
console.log(typeof 123) //number
console.log(typeof 'asd') //string
console.log(typeof false) //boolean
console.log(typeof null) //object
console.log(typeof {}) //object
console.log(typeof []) //object
console.log(typeof console.log) //function